PCR: polymerase chain reaction. It is a molecular biology technique for amplifying and amplifying specific DNA fragments. It can be regarded as a special DNA replication in vitro. The biggest feature of PCR is the ability to increase the amount of DNA. Schematic diagram of PCR principle: The types of PCR instruments are: conventional ordinary PCR instrument, gradient PCR instrument, in situ PCR instrument, real-time fluorescence quantitative PCR instrument four categories! 1, ordinary PCR instrument A PCR machine that can only run a specific annealing temperature is called a common PCR instrument, that is, a conventional PCR instrument. If you want to use it for different annealing temperatures, you need to run multiple times. Ordinary PCR instruments are mainly used in scientific research, teaching, clinical medicine, inspection, quarantine, etc. 2. Gradient PCR instrument: One-time PCR amplification can be set up as a gradient PCR machine with a range of different annealing temperature conditions (typically 12 temperature gradients). Different DNA fragments have different annealing temperatures, and are amplified by setting a series of gradient annealing temperatures, so that one-time PCR amplification can screen out the most suitable annealing temperature for efficient amplification. Gradient PCR machines are mainly used to study the amplification of unknown DNA annealing temperatures, which saves time and costs. It can also be used for ordinary PCR without setting a gradient. Gradient PCR instruments are widely used in scientific research and teaching institutions. 3. Real-time fluorescence quantitative PCR instrument On the basis of the design of the common PCR instrument, a fluorescent signal excitation and acquisition system and a computer analysis processing system are added to form an instrument with a fluorescent quantitative PCR function. The principle of PCR amplification is the same as that of ordinary PCR amplification. The primers added during PCR amplification are labeled with isotopes, fluorescein, etc., and primers and fluorescent probes are used to simultaneously bind to the template for specific amplification. The results of the amplification are transmitted to the computer analysis and processing system through the real-time acquisition signal connection of the fluorescence signal acquisition system, and the quantized real-time result output is obtained. The real-time PCR instrument has a single channel, two channels and multiple channels. When only one fluorescent probe is used, a single channel is used; when there are multiple fluorescent labels, multiple channels are used. The single channel can also detect multi-fluorescence markers and target gene expression products, because only one amplification of the target gene can be detected at a time, and multiple amplifications are required to detect the amount of different target gene fragments. Multi-channel facilitates multiplex PCR to achieve the function of detecting multiple genes of interest at a time. Application of real-time PCR instrument: (1) Animal disease detection: Avian influenza, foot-and-mouth disease, swine fever, Salmonella, Escherichia coli, Actinobacillus pleuropneumoniae, parasitic diseases, etc., Bacillus anthracis. (2) Food safety: detection of food source microorganisms, food allergens, genetically modified, and dairy companies, Enterobacter sakazakii. (3) Scientific research: quantitative research on medicine, agriculture, animal husbandry, biological related molecular biology, universities and research institutes. 4, in situ PCR instrument: It is an intracellular gene amplification instrument for localization analysis of target DNA from cells. Such as the location of the pathogenic gene in the cell or the location of the target gene in the cell. The integrity of the cells or tissues can be maintained, and the PCR reaction system can be infiltrated into tissues and cells, and gene amplification can be performed at the position where the target DNA of the cells is located. Not only can the target DNA be detected, but the position of the target sequence within the cell can also be indicated. It is of great practical value to study the pathogenesis, clinical process and pathological changes of diseases at the molecular and cellular levels. Whether you`re stressed from a long day at work or treating yourself to an at-home spa day, using an electric foot massager is the next best thing to seeing a professional. Electric Foot Massagers,Vibrating Foot Massager,Reflexology Foot Massager Ningbo Shuangtuo International Trade Co., Ltd. , https://www.nbst-sports.com
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